Merge pull request #75794 from ian-twilightcoder/swiftremotemirror_buildfix

[cherry-pick release/6.0]Build fix for when the Darwin module is split up

Author: ian-twilightcoder

tools/swift-inspect/Sources/swift-inspect/Operations/DumpConcurrency.swift

@@ -14,6 +14,9 @@
 
 import ArgumentParser
 import SwiftRemoteMirror
+#if canImport(string_h)
+import string_h
+#endif
 
 struct DumpConcurrency: ParsableCommand {
   static let configuration = CommandConfiguration(